Introduction
Engine 49 and Rescue 7 respond to a report of child not breathing. They arrive to find a screaming mother holding a 6-month-old boy who is apneic and pulseless. The mother found the child unresponsive after placing the child down for a nap about 15 minutes ago. Paramedic Harris takes the child from the mother, begins cardiopulmonary resuscitation (CPR) and moves quickly to the ambulance.
Once inside, Harris discovers organized electrical activity at a rate of 20 complexes per minute, but the child remains pulseless. Paramedic Garcia attempts to establish intraosseous access while Harris tries to secure the airway with an endotracheal (ET) tube. Garcia gains intraosseous access quickly; however, multiple intubation attempts fail to secure the airway.
After a 45-minute resuscitation attempt in the local emergency department, the physician declares futility and terminates all further resuscitation efforts.
On the way back to the station, Harris wonders whether an alternative form of airway control would have resulted in a different outcome.
Review
Researchers in Pennsylvania designed a pilot study to examine two issues related to the use of a pediatric supraglottic airway (Ritter & Guyette 2011). First, the researchers wanted to know if previous training with an adult supraglottic airway (SGA) was sufficient for EMS crews to demonstrate proficiency with a pediatric version of the same airway in a simulated respiratory arrest case. Second, they wanted to learn the preferences and perceptions of participants toward the device compared to other forms of airway control, such as the ET tube.
During the yearly skills review, researchers asked 45 flight nurses and paramedics to attempt successful placement of a pediatric King LT-D in a human simulator. Before the study, this particular pediatric airway was not part of the normal equipment carried by the air rescue service. However, each crew member had previous experience with an adult version of the SGA in both simulated and real patient contacts.
Researchers recorded whether the attempt was successful, the number of attempts required for successful insertion and how long the patient went without a breath while each crew member attempted insertion. In order to ensure accuracy, the researchers videotaped each attempt and measured time intervals from the recording.
The research team used an 11-point grading checklist to score individual crew member performance. A score of eight or better indicated competency in the airway management procedure. At the end of the exercise, each medic answered a series of questions concerning the device using a five-point Likert scale anchored at 1 = strongly agree to 5 = strongly disagree.
Results
Twenty-three of the 45 crew members (51 percent) were nurses, and the remainder were paramedics. The median average duration of employment with the air medical system was four years (range two to 12 years). The overwhelming majority of the team (95.5 percent) successfully inserted the pediatric airway on the first attempt in an average of 34 seconds (95 percent CI 26.4-67.3). Four members required two attempts; two of those resulted in successful insertions, and two did not.
Using the checklist, researchers determined that 90 percent of the crew members were competent in pediatric King LT-D insertion despite never having used the device before.
The most commonly missed step in the checklist was lubrication of the airway before insertion (30 percent completed), followed by preparation and checking equipment (60 percent completed), preoxygenation (66 percent completed) and failure to secure the airway after confirming successful insertion (73 percent completed).
Most crew members agreed or strongly agreed that their previous training and experience with the adult version of the King LT-D adequately prepared them for using the pediatric version. Most agreed that it was easier to insert the device than an ET tube and strongly agreed that they would use it as an alternative device for securing the pediatric airway. However, the crew strongly disagreed that they would use the King LT-D as the primary method of securing the pediatric airway.
What it means for you
The most recent version of the American Heart Association Emergency Cardiovascular Care guidelines places a higher priority on chest compressions than on ventilation for adult victims of cardiac arrest (Field et al. 2010). In general, however, the etiology of pediatric cardiac arrest is different from that of an adult (Berg, M. D. et al. 2010).
More specifically, infants and children more frequently develop cardiac arrest because of a progressively worsening hypoxic event (Kleinman et al. 2010). Respiratory failure develops, leading to bradycardia and hypotension and culminating in cardiac arrest (Young & Seidel 1999). It is therefore reasonable to believe that early effective ventilation may be more important for these patients than for adult victims of cardiac arrest.
In many systems, training and logistics limit paramedics to two forms of airway management and ventilation for small children. Basic techniques include head positioning, simple adjuncts and bag-mask ventilation. Advanced procedures usually involve only endotracheal intubation (ETI).
More than a decade ago, researchers in Los Angeles demonstrated that ETI did not provide greater survival or neurological advantages for pediatric patients suffering an out-of-hospital cardiac arrest when compared to use of the bag-valve mask (BVM) (Gausche et al. 2000).
In fact, three subgroups of children actually experienced significantly worse outcomes when paramedics attempted to place an endotracheal tube. Researchers in Northern California found a 46 percent complication rate and no statistical differences in outcome when paramedics performed ETI in children under the age of 19 years compared to airway management with a BVM (Aijian, Tsai, Knopp, & Kallsen 1989).
Spanish researchers studying cardiac arrest in children under the age of 16 years found the risk of death was 2.5 times higher if paramedics performed ETI (Lopez-Herce et al., 2005). A retrospective evaluation of data from the National Pediatric Trauma Registry could find no survival advantage offered by paramedic ETI for pediatric patients with severe head injury compared to treatment with a BVM (Cooper et al. 2001).
A Dutch pre-hospital pediatric study found statistically significant increases in mortality if paramedics performed ETI compared to endotracheal intubation by physicians (95 percent vs. 37 percent, respectively; p < .001) (Gerritse, Th Draaisma, Schalkwijk, van Grunsven, & Scheffer 2008).
Perhaps one explanation for the poor outcomes associated with ETI for victims of cardiac arrest is that many providers must interrupt chest compressions to intubate successfully. Within a few seconds of the interruption, blood flow through coronary arteries ceases (Paradis et al. 1990; Valenzuela et al. 2005; Wik et al. 2005), a detrimental consequence called the no-flow time (NFT).
Adult simulation studies suggest that healthcare providers of many disciplines can reliably insert the King LT-D airway while minimizing interruptions in chest compressions, thereby reducing or even eliminating NFT (Wiese, Bartels, Bergmann et al. 2008; Wiese, Bartels, Schultens et al. 2008) (Wong, Lim, & Gan 2007). The 2010 American Heart Association Guidelines for CPR (Berg, R. A. et al. 2010) emphasize the importance of reducing no-flow time.
Limitations
One important limitation of this study is in participant selection. This sample involved air medical providers with roughly equal participation of critical nurses and paramedics. The training level and skill proficiency maintenance of this group may not accurately represent those characteristics in another sample of prehospital care providers.
Another limitation lies in fact that this is a manikin study. The conditions under which the participants inserted the pediatric airway may have simulated actual field conditions; however, they were not actual field conditions. The literature is ripe with manikin and animal evidence that does not translate well when applied to human beings.
Supraglottic airways are recent introductions to the EMS discipline. We still do not definitively know about the risk/benefit ratio of the devices and whether they truly improve outcomes in real people. Although we should remain cautious, we must be careful not to discount evidence that IS available.
One of the most interesting results of this study is that the participants judged the device to be easier to insert than a pediatric endotracheal tube, but they strongly disagreed with using it as a primary means of airway control in the pediatric patient. If one truly believes that airway control is paramount to achieving a successful outcome following cardiac arrest, the logical conclusion is that the preferred method of airway control be the method that accomplishes effective ventilation but is easiest to perform.
Despite the lack of efficacy evidence for ETI of pediatric patients who suffer cardiac arrest, there are significant barriers to replacing the procedure with an alternative form of airway control (Youngquist, Gausche-Hill, Squire, & Koenig 2010).
Thomas Kuhn (1996) argues that scientific revolution within a certain discipline (such as EMS) occurs when an evidence-based paradigm replaces a previous paradigm. Paramedics began intubating pediatric patients because it was the only airway control device available at the dawn of EMS, not because scientific evidence demonstrated it was the best thing to do in the prehospital environment.
The current evidence suggests that by performing ETI, we may be hurting more children than we are helping. Outcome data following supraglottic airway insertion in the pediatric patient is lacking. EMS must decide whether we accept the evidence and become a profession or continue to hold on to our talismans, leeches and potions.
References
Aijian, P., Tsai, A., Knopp, R., & Kallsen, G. W. (1989). Endotracheal intubation of pediatric patients by paramedics [abstract]. Annals of Emergency Medicine, 18(5), 489-494. doi:10.1016/S0196-0644(89)80830-3
Berg, M. D., Schexnayder, S. M., Chameides, L., Terry, M., Donoghue, A., Hickey, R. W., Berg, R. A., Sutton, R. M., & Hazinski, M. F. (2010). Part 13: Pediatric basic life support: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation, 122(suppl 3), S862-S875. doi:10.1161/CIRCULATIONAHA.110.971085
Cooper, A., DiScala, C., Foltin, G., Tunik, M., Markenson, D., & Welborn, C. (2001). Prehospital endotracheal intubation for severe head injury in children: A reappraisal. Seminars in Pediatric Surgery 10(1), 3-6.
Field, J. M., Hazinski, M. F., Sayre, M. R., Chameides, L., Schexnayder, S. M., Hemphill, R., Samson, R. A., Kattwinkel, J., Berg, R. A., Bhanji, F., Cave, D. M., Jauch, E. C., Kudenchuk, P. J., Neumar, R. W., Peberdy, M. A., Perlman, J. M., Sinz, E., Travers, A. H., Berg, M. D., Billi, J. E., Eigel, B., Hickey, R. W., Kleinman, M. E., Link, M. S., Morrison, L. J., O’Connor, R. E., Shuster, M., Callaway, C. W., Cucchiara, B., Ferguson, J. D., Rea, T. D., & Vanden Hoek, T. L. (2010). Part 1: Executive summary: 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 122(suppl 3), S640 –S656. doi:10.1161/CIRCULATIONAHA.110.970889
Gausche, M., Lewis, R. J., Stratton, S. J., Haynes, B. E., Gunter, C. S., Goodrich, S. M., Poore, P. D., McCollough, M. D., Henderson, D. P., Pratt, F. D., & Seidel, J. S. (2000). Effect of out-of-hospital pediatric tracheal intubation on survival and neurological outcome: A controlled clinical trial. Journal of the American Medical Association, 283(6), 783-790. doi:10.1001/jama.283.6.783
Gerritse, B. M., Th Draaisma, J. M., Schalkwijk, A., van Grunsven, P. M., & Scheffer, G. J. (2008). Should EMS-paramedics perform paediatric tracheal intubation in the field? Resuscitation, 79(2), 225-229. doi:10.1016/j.resuscitation.2008.05.016
The author has no financial interest, arrangement, or direct affiliation with any corporation that has a direct interest in the subject matter of this presentation, including manufacturer(s) of any products or provider(s) of services mentioned.
Send correspondence concerning this article to Kenneth W. Navarro, The University of Texas Southwestern Medical School at Dallas, 6300 Harry Hines Blvd, MC 9134, Dallas, Texas 75390-9134. E-mail: kenneth.navarro@utsouthwestern.edu
